feb 1, 1968 - Treaty on Non-Proliferation of Nuclear Weapons .
Description:
Treaty on Non-Proliferation of Nuclear Weapons , is an international treaty whose objective is to prevent the spread of nuclear weapons and weapons technology, to promote cooperation in the peaceful uses of nuclear energy.
source: https://en.wikipedia.org/wiki/Treaty_on_the_Non-Proliferation_of_Nuclear_Weapons
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